On the computations of gassolid mixture two phase flow article pdf available in advances in applied mathematics and mechanics 61. Most solid rocket propellants produce combustion products that are a mixture of gases and condensed phase particles either liquid or solid which is evident as visible smoke in the exhaust plume. Simulation of granular twophase flow universiteit twente. When removing particulate matter from liquid, a hydrocyclone is used. In many cases in which the flow phenomena are dominated by one phase and the amounts of the other, unimportant phases are small like dusty gas flows, small gas bubbles in a liquid, multiphase flow is in practice. Visualization of twophase reacting flow behavior in a gas. Many researches were carried out to correlate differential pressure and void fraction in two phase. It has long been recognized that the online measurement of gas solid two phase flow is a technically challenging area. Introduction some of the important features of the flow of two phase mixtures composed of a liquid together with a gas or vapour are discussed in this section. The canadian journal of chemical engineering 1996, 74 6, 10251027.
Analysis of a fluid energy mill fem by gas solid two phase. These types could be predicted using the following process. Calculating twophase pressure drop river city engineering. Physical phases of matter are gas, liquid, and solid, but the concept of phase in a multiphase. Cfd simulation of gassolid twophase flow in pneumatic.
Edwards, methodology for sizing relief valves for twophase gasliquid flow, proceedings of the process plant. A selfconsistent physical model of the bubbles in a gas solid two. Based on cfd model framework, a simulation analysis of gas solid two phase flow in a multicavity kiln used for heating catalysts is presented. In some cases these velocities are higher than desirable for a process piping system. In these studies, some effects such as coupling effect and velocity lag are absence.
In a large number of engineering operations where vertical, cocurrent, two phase flow occurs, a particular. The dense phase gas solid two phase flow in horizontal pipes is very complicated because of the gravity acting perpendicular to the flow direction. Studies on three phase liquid gas solid flow hydrodynamics are rather scarce. Part ii discusses selected gas solid flow systems such as gas solid separators, hopper and standpipe flows, fluidized beds, and pneumatic conveying systems. Mean volumetric void fraction is a key parameter to characterise two phase flows. Part i deals with basic relationships and phenomena, including particle size and properties, collision mechanics, heat, mass, and momentum transfer. In gas solid and gas liquid mixtures, the gas will always be the lighter phase, and in liquid solid systems it will be usual for the liquid to be less dense than the solid. In vertical upward flow, therefore, there will be a tendency for the lighter phase to rise more quickly than the denser phase giving rise to a slip velocity. Relief valves for two phase gas liquid flow, chemical engineering, 109, no. Summary of flow regimes and pressure drop correlations in. K bo static bond number c p g gas heat capacity jkg. Sediment transport in rivers is subject to multiphase flow, in which the suspended particles are treated as a disperse second phase which interacts with the continuous fluid phase. Analysis of fluid energy mill by gassolid twophase flow.
Those propellants containing metals, such as aluminum or magnesium, generate oxides of the metals as condensed phase combustion products. There are many of documented experimental and nu merical studies relating to gas particle two phase flows in channels and ducts involving curved 90. Basically, the size reduction in the fluid energy mill is achieved by intensive particulate collisions inside the gas solid two phase flow. The dynamics and thermal history of particles in gases also affect the. Such high velocities can cause a phenomenon known as erosion corrosion in equipment and piping systems. The dense phase gas solid flow is comprised of two layers moving side by side. The study reported in this thesis is concerned with the granular dynamics of gassolid two phase flows. The most common class of multiphase flows are two phase flows, and these include the following. The most common class of multiphase flows are twophase flows, and these include the following. Simulation on velocity field of gas solid flow in the abrasive air jet nozzle was studied by the computed fluid dynamicscfd software.
Pdf on the computations of gassolid mixture twophase flow. Examples of solid liquid flow include flow of corpuscles in the plasma, flow of mud, flow of liquid with suspended solids such as slurries, motion of liquid in aquifers. Flow regimes determine the macroscopic behavior of. Dry cleaning of coal becomes increasingly significant to improve energy efficiency and reduce air pollutant emissions. Studies on threephase liquidgassolid flow hydrodynamics are rather scarce. Two phase flow involving phase change between the liquid and vapor phases of a single substance is of particular interest to the heat transfer community and to practicing. Cyclonic separation is a method of removing particulates from an air, gas or liquid stream, without the use of filters, through vortex separation. Two phase flow can be solid liquid flow, liquidliquid flow, gas solid flow, and gas liquid flow. In contrast, most existing models neglect viscous and heat conduction effects, and, thus, can characterize only the wave propagation in a two phase flow. Two phase flow, which involves fluid flow of a mixture of two phases, can be 1 liquidvapor flow, 2 liquidliquid, 3 liquid solid particles, and 4 gas solid particles. Rotational effects and gravity are used to separate mixtures of solids and fluids. This study only focuses on the two phase flow inside the fem and the particle breakage process is beyond the scope.
Depending upon the flow regime, the liquid in a two phase flow system can be accelerated to velocities approaching or exceeding vapour velocities. Analysis of a fluid energy mill fem by gas solid two phase flow simulation presented by. A novel physical mechanism of liquid flow slippage on a solid. Unsteady state gasliquid slug flow through vertical pipe. Karakteristike dvofaznog protoka plincvrsta tvar u. Multiphase flow is the simultaneous flow of several phases. Gas liquid two phase flow simulation in spipe duration. There are many applications in the chemical and process industries, ranging from the flow of mixtures of oil and gas. Flow type the flow type of twophase liquidgas flow can be characterized into one of seven types shown in figure 1. Two phase flow refers to the interactive flow of two distinct phases with common interfaces in a channel, with each phase representing a mass or volume of matter. Types of phase flows and gas liquid system piping guide.
This book is an undertaking of a pioneering work of uniting three vast fields of interfacial phenomena, rheology and fluid mechanics within the framework of solid liquid two phase flow. The hydrodynamic characteristics of gasliquid twophase flow can significantly affect the performance of gasliquidsolid microreactors. The system is sandwiched by two parallel flat solid walls, and the flow direction is the x direction. Experimental and numerical study of dilute gassolid flow. Research of gassolid twophase flow capacitance cross. Fischertropsch synthesis and also addresses sections 1 and 2 on gas solid flow regimes for intermediate stokes numbers shell oil is partially supporting this work as part of the nsfiucrc center in particulate.
Gasliquid two phase flow simulation in spipe youtube. Detection of gassolid twophase flow based on cfd and. Effects of pressure and temperature on flow regimes in gas solid fluidization systems. Two domensional simulation of velocity field of twophase. Argonwater is an instance of two phase two component flow. Dec 18, 2008 bubble flow, slug flow and emptyfullempty flow in fluid applications duration. Oct 10, 20 solidworks flow simulation 2014 cfd demo. Hydrodynamic and thermal fields analysis in gassolid two. Effect of stokes number on turbulent fluidsolid flows. By using montecarlo method, the gas solid two phase flow model is established.
Numerical simulations of liquidgas solid threephase flows. Linjie zhu, zheng qian ppi national defense industrial association conference may 1720, 2010 distribution statement a. Numerical simulations of liquidgas solid threephase. Fine coal dry cleaning processes are mostly based on gas. Airwater is an example of two phase multi component flow. Amir faghri, yuwen zhang, in transport phenomena in multiphase systems, 2006. Simulations were performed with a fixed solids influx at the bottom, which allowed investigation.
These types could be predicted using the following process parameters. A gas solid flow is characterized by the flow of gases with suspended solids. Multiphase flow occurs regularly in many natural phenomena, and also is well documented and crucial within various industries. Flow regime diagrams for gas solid fluidization and upward transport.
Use the link below to share a fulltext version of this article with your friends and colleagues. When a nozzle jet was injected, secondary flow of the jet exited in the vicinity of the riser wall due to vortices, and this flow moved forth at first and then merged into the main stream. The gas solid two phase flow in the riser has been simulated with a 3d, hard sphere, discrete particle model, applying a subgrid scale sgs model to account for the influence of the gas phase turbulence using the model recently proposed by vreman 1. Twophase flow can occur in various forms, such as flows transitioning from pure liquid to vapor as a result of external heating, separated flows, and dispersed two phase flows where one phase is present in the form of particles, droplets, or bubbles in a continuous carrier phase i. The two phases can exist as combinations of solid, gas andor liquid phases. Micro motion coriolis flow and density measurement 3,974 views. Sundaresan, analysis of the flow in inhomogeneous particle beds using the spatially averaged twofluid equations, int.
The method can also be used to separate fine droplets of. Freesurface flows can be described as stratified two phase flows. Much work has been carried out in the field of gas solids two phase flow measurement over the past three decades. The gas phase may either be the vapor of the liquid being accelerated, in which case the flow is termed one. The simulation was based on the lagrangian method for the solid phase, where trajectories of many particles are calculated by integrating the equations of motion. Khalaiji oskouei t arbiat modares university abstract sand particles present in the fluid flows extracted from oil wells causes many problems for oil and gas production companies. Void fraction measurement of gasliquid twophase flow. Pressure variations are inevitable in most two phase. Gassolid twophase flows are encountered in a wide variety of industrial applications. Numerical simulation research on gassolid two phase flow in oil.
Flow quality flow rate flow regime low low and intermediate bubbly high dispersed bubbly. These processes are frequently encountered in the process industries. Numerical study of unsteady gas solid two phase flow around a circular cylinder employing eulerianlagrangian model. Pdf computational fluid dynamics cfd simulations of dilute gassolid flow through a curved 90. Pipelines carrying two phase fluids liquid and gas are called two phase flow. In this paper, a gasparticle computational fluid dynamics cfd flow model was developed based on the eulerian twofluid model. A gassolid flow is characterized by the flow of gases with suspended solids.
Digital image processing based mass flow rate measurement. A computational study of the gassolid suspension flow. In fluid mechanics, twophase flow is a flow of gas and liquid a particular example of multiphase flow. Hydrodynamic and thermal fields analysis in gas solid two phase flow. Work directly addresses section 3 on liquid solid flows of doe multiphase flow roadmap e. Actually, the terms two component flow and two phase flow are often used rather loosely in the literature to mean liquid gas flow and liquidvapor flow respectively. For the student or researcher in the field of multiphase flow this broad spectrum presents.
The analysis of two phase flow piping is more complex and less understood than that of incompressible or compressible fluid flow. Twophase gasliquid solid flow modelling in 90 bends and its effect on erosion by m. Pdf numerical study of unsteady gassolid twophase flow. The engineers developed the terminology rather than the chemists. In general, the measurement methods can be classified into two categories, direct method and indirect method. The study of multiphase flow is very important in energyrelated. The heat transfer model includes radiation exchange among gas, refractory shell and catalyst, conduction inside the refractory. The solid phase concentration measurement of gas solid two phase flow is one of the most difficult parameters to be measured, which has always been the research focus and difficulty in industrial. We impose a periodic boundary condition to x direction.
Effect of the gassolid twophase flow velocity on elbow. Numerical simulation of gassolid twophase flow in a two. In granular dynamics simulations the newtonian equations of motion are solved for each individual particle in the system while taking into account the mutual interaction between particles and between particles and walls. Introduction gas liquid two phase flow in pipes is a common occurrence in the petroleum industry production and transportation of oil and gas. The effect of the nozzle diameter on the velocity field shows that the velocity field in the nozzle with a smaller diameter is more welldistributed. The chapter will use the basic concepts learned in earlier chapters and show the technological and design application to gas solid reactions. This type of flow is fundamental to many industrial processes such as pneumatic transport, particulate pollution control, combustion of pulverized coal, drying of food products, sand blasting, plasmaarc coating and fluidized bed mixing. The modeling of gas particles flows in horizontal channels with different wall roughness was made by sommerfeld et al.
Flow type the flow type of two phase liquid gas flow can be characterized into one of seven types shown in figure 1. Particlewall collisions turned out to have very little influence on the flow structure. Although multiphase flow involving three phases can also. Notes on twophase flow, boiling heat transfer, and boiling.
Actually, the terms two component flow and twophase flow are often used rather loosely in the literature to mean liquid gas flow and liquidvapor flow respectively. Numerical simulation of swirling gassolid two phase flow through a. The velocity field of the two phase flow in the abrasive air jet nozzle can be obtained by means of simulation. Gas solid twophase flow is a complex flow system composed of gas and solid particles, and represents an important branch of fluid dynamics. Two phase flow is any type of flow containing more than one phase of liquid, gas or solid. Multiphase flow in annular channels is complex, particularly in the region where the flow direction abruptly changes between the inner pipe and the outer pipe. Analysis of a fluid energy mill fem by gas solid two. A two phase nozzle is a nozzle in which a liquid and a gas are mixed at high pressure and low velocity and expanded to low pressure and high velocity. Method for measurement of local solid flux in gassolid. In general in a gas solid system, the mechanisms and formulation of interaction forces have been investigated, starting from studies on the dynamics of a single particle, by many authors710. Using nitrobenzene hydrogenation as the reference heterogeneous catalytic reaction, the twophase reacting flow behavior was visualized and characterized. Gas solid catalytic reactions this chapter will focus in more details on reactions between components in the gas phase catalyzed by a solid catalyst. This is probably the most important form of multiphase flow, and is found widely in a whole range of industrial applications.
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